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August 18, 2005
At the track
Yesterday I took my supercharged RSX to Sacramento Raceway. I had never raced it before and was wondering how it'd do. Based on experience on the street I expected to have plenty of power, but not enough traction. And that is exactly how it turned out. Needless to say, I took my notebook with me so I could datalog and study my runs on the K-Pro's K-Manager software.
On my first run I basically just sat there at the starting line, spinning my wheels. I had launched at perhaps 5000 rpm and it was like the wheels were spinning in butter. I must have just stood still for a good two or three seconds. I still managed a trap speed of over 103 miles per hour, but the time was miserable, high 14s. I analyzed the datalog, found that at least my air-fuel ratio was perfect and that the engine had no knocks at all, and that even my intake air temperature wasn't too bad. I also found that the IAT can drop by as much as 20 degrees Fahrenheit over a single 1/4-mile pass.
I did six runs in total, each with a different launch technique. Nothing worked as my 225/45-17 Kumho Excsta 712 tires were simply overmatched by the 260 wheel horsepower of the rather light car. My trap speed was consistently in the mid 103s, but I never managed better than a 14.1 through the quarter. In general, a trap speed of almost 104 mph should be good enough for mid 13 runs.
Before my last run I all of a sudden had a Check Engine light. Normally that would be cause for serious concern. However, with the notebook attached to the ECU I could quickly determine that the error code was for a lean condition that did not worry me. I am running experimental fuel injectors that are lean in closed loop where the ECU corrects via short term fuel trim, but run rich enough in open loop. Thanks to the Hondata K-Pro, I could diagnose that MIL on the fly and erase it as I was driving up to the starting line.
This morning I ordered a set of Falken 615RT tires. They are far stickier than the Kumhos and should make a difference. I could have simply gotten a set of true drag radials on stock wheels, but I don't like changing wheels and I do like traction on the street as well, so the Falkens may be a good compromise.
Posted by conradb212 at August 18, 2005 2:01 PM